The lens is a critical component of any machine vision or vision system. The most sensitive image sensor on the market won’t be of any use if it’s not paired with the right lens. Clearly, any image quality problems arising from an improper lens will affect the entire vision system. Choosing the right lens is important and will impact your vision system over its entire lifetime. But with so many different types of lenses and lens manufacturers, how do you know which machine vision lens is right for you?
Lens Pixel Size, Not Pixel Number, is a Key Consideration for Machine Vision Lens Selection
The first thing most people look for is how many pixels a lens is built for, but this is slightly misleading. The resolving power of a lens is based on how small of a spot it can resolve. In other words, how small of a spot it can “see.”
You need to understand the pixel size and the number of pixels in order to find the right lens you need. Not all 5 Megapixel lenses are the same. Lenses with pixels that are too large for the imaging area are going to cause low quality images.
Other Key Considerations for Machine Vision Lens Selection
The physical specifications of your application will determine which lens is best for you. There are a few basic considerations everyone must account for:
- Working distance: the distance of the object being captured.
- Field of view: the area being captured by the lens.
- Camera mount: not all lenses will be compatible with your camera’s mount.
- Sensor size: a lens has to be at least as big as the size of your camera’s sensor.
While there are certainly many other factors to consider, the few mentioned above are a great place to start. Once you know these, you can start to narrow down your options.
Choosing a machine vision lens is not always straight forward, and there’s a lot riding on the decision. Lens compatibility affects the performance of your entire vision system.
If you need assistance choosing a lens, try out our machine vision lens selector tool.